A person who has had very serious and very recent problems with binge use of a drug that's related to the one being prescribed? That is 100% the doctor's business.

The doctor is a busy person, he has to factor in many things into a treatment. The attitude of the 4 y.o. child running to his mom crying because he did something bad is not something any doctor should have to deal with. He's an adult, he drugged his head and bared the consequences.

His doctor needs to know important things like hereditary illnesses, family history, blood test results, medication etc. He doesn't need to know what goes on in his household. That's his privacy. It's intimate and no one should know it.